The present invention relates to a new family of genes encoding lepidopteran-toxic proteins and insecticidal fragments thereof. In particular, the present invention is directed to exemplary proteins designated herein as TIC900, TIC402, TIC403, TIC404, TIC961, TIC962, TIC963, TIC965 and TIC966, and insecticidal fragments thereof, each encoded by exemplary nucleotide coding sequences designated herein respectively as tic900, tic402, tic403, tic404, tic434, tic961, tic962, tic963, tic965, and tic966, as well as to nucleotide sequence homologs that (1) encode insecticidal proteins and (2) hybridize to the tic900, tic402, tic403, tic404, tic434, tic961, tic962, tic963, tic965, and tic966 coding sequences under stringent hybridization conditions. The present invention also relates to host cells transformed with one or more nucleotide sequences of the present invention or transformed with variants of the nucleotide sequences set forth herein, genes related by identity and/or similarity to the sequences set forth herein, and/or homologs thereof, particularly those sequences that have been modified for improved expression in plants. In a preferred embodiment, the transformed host cells are plant cells.
Almost all field crops, plants, and commercial farming areas are susceptible to attack by one or more insect pests. Particularly problematic are Coleopteran and Lepidoptern pests. For example, vegetable and cole crops such as artichokes, kohlrabi, arugula, leeks, asparagus, lentils, beans, lettuce (e.g., head, leaf, romaine), beets, bok choy, malanga, broccoli, melons (e.g., muskmelon, watermelon, crenshaw, honeydew, cantaloupe), brussels sprouts, cabbage, cardoni, carrots, napa, cauliflower, okra, onions, celery, parsley, chick peas, parsnips, chicory, peas, chinese cabbage, peppers, collards, potatoes, cucumber, pumpkins, cucurbits, radishes, dry bulb onions, rutabaga, eggplant, salsify, escarole, shallots, endive, soybean, garlic, spinach, green onions, squash, greens, sugar beets, sweet potatoes, turnip, swiss chard, horseradish, tomatoes, kale, turnips, and a variety of spices are sensitive to infestation by one or more of the following insect pests: alfalfa looper, armyworm, beet armyworm, artichoke plume moth, cabbage budworm, cabbage looper, cabbage webworm, corn earworm, celery leafeater, cross-striped cabbageworm, european corn borer, diamondback moth, green cloverworm, imported cabbageworm, melonworm, omnivorous leafroller, pickleworm, rindworm complex, saltmarsh caterpillar, soybean looper, tobacco budworm, tomato fruitworm, tomato hornworm, tomato pinworm, velvetbean caterpillar, and yellowstriped armyworm. Likewise, pasture and hay crops such as alfalfa, pasture grasses and silage are often attacked by such pests as armyworm, beef armyworm, alfalfa caterpillar, European skipper, a variety of loopers and webworms, as well as yellowstriped armyworms.
Fruit and vine crops such as apples, apricots, cherries, nectarines, peaches, pears, plums, prunes, quince almonds, chestnuts, filberts, pecans, pistachios, walnuts, citrus, blackberries, blueberries, boysenberries, cranberries, currants, loganberries, raspberries, strawberries, grapes, avocados, bananas, kiwi, persimmons, pomegranate, pineapple, and tropical fruits are often susceptible to attack and defoliation by achema sphinx moth, amorbia, armyworm, citrus cutworm, banana skipper, blackheaded fireworm, blueberry leafroller, cankerworm, cherry fruitworm, citrus cutworm, cranberry girdler, eastern tent caterpillar, fall webworm, fall webworm, filbert leafroller, filbert webworm, fruit tree leafroller, grape berry moth, grape leaffolder, grapeleaf skeletonizer, green fruitworm, gummosos-batrachedra commosae, gypsy moth, hickory shuckworm, hornworms, loopers, navel orangeworm, obliquebanded leafroller, omnivorous leafroller. omnivorous looper, orange tortrix, orangedog, oriental fruit moth, pandemis leafroller, peach twig borer, pecan nut casebearer, redbanded leafroller, redhumped caterpillar, roughskinned cutworm, saltmarsh caterpillar, spanworm, tent caterpillar, thecla-thecla basillides, tobacco budworm, tortrix moth, tufted apple budmoth, variegated leafroller, walnut caterpillar, western tent caterpillar, and yellowstriped armyworm.
Field crops such as canola/rape seed, evening primrose, meadow foam, corn (field, sweet, popcorn), cotton, hops, jojoba, peanuts, rice, safflower, small grains (barley, oats, rye, wheat, etc.), sorghum, soybeans, sunflowers, and tobacco are often targets for infestation by insects including armyworm, asian and other corn borers, banded sunflower moth, beet armyworm, bollworm, cabbage looper, corn rootworm (including southern and western varieties), cotton leaf perforator, diamondback moth, european corn borer, green cloverworm, headmoth, headworm, imported cabbageworm, loopers (including Anacamptodes spp.), obliquebanded leafroller, omnivorous leaftier, podworm, podworm, saltmarsh caterpillar, southwestern corn borer, soybean looper, spotted cutworm, sunflower moth, tobacco budworm, tobacco hornworm, and velvetbean caterpillar.
Bedding plants, flowers, ornamentals, vegetables and container stock are frequently fed upon by a host of insect pests such as armyworm, azalea moth, beet armyworm, diamondback moth, ello moth (hornworm), Florida fern caterpillar, Io moth, loopers, oleander moth, omnivorous leafroller, omnivorous looper, and tobacco budworm.
Forests, fruit, ornamental, and nut-bearing trees, as well as shrubs and other nursery stock are often susceptible to attack from diverse insects such as bagworm, blackheaded budworm, browntail moth, california oakworm, douglas fir tussock moth, elm spanworm, fall webworm, fruittree leafroller, greenstriped mapleworm, gypsy moth, jack pine budworm, mimosa webworm, pine butterfly, redhumped caterpillar, saddleback caterpillar, saddle prominent caterpillar, spring and fall cankerworm, spruce budworm, tent caterpillar, tortrix, and western tussock moth. Likewise, pests such as armyworm, sod webworm, and tropical sod webworm often attack turf grasses.
Because crops of commercial interest are often the target of insect attack, environmentally-sensitive methods for controlling or eradicating insect infestation are desirable in many instances. This is particularly true for farmers, nurserymen, growers, and commercial and residential areas which seek to control insect populations using eco-friendly compositions.
Bacillus thuringiensis is a gram-positive bacterium that produces proteinaceous crystalline inclusions during sporulation. These B. thuringiensis crystal proteins are often highly toxic to specific insects. Insecticidal activities have been identified for crystal proteins from various B. thuringiensis strains against insect larvae from the insect orders Lepidoptera (caterpillars), Coleoptera (beetles) and Diptera (mosquitoes, flies).
Individual B. thuringiensis crystal proteins, also called delta-endotoxins or parasporal crystals or toxin proteins, can differ extensively in their structures and insecticidal activities. These insecticidal proteins are encoded by genes typically located on large plasmids, greater than 30 mega Daltons (mDa) in size, that are found in B. thuringiensis strains. A number of these B. thuringiensis toxin genes have been cloned and the insecticidal crystal protein products characterized for their specific insecticidal properties. Hofte et al. (1989) and Schnepf et al. (1998) provide reviews of B. thuringiensis toxin genes and crystal proteins.
The insecticidal properties of B. thuringiensis have been long recognized, and B. thuringiensis strains have been incorporated in commercial biological insecticide products for over forty years. Commercial B. thuringiensis insecticide formulations typically contain dried sporulated B. thuringiensis fermentation cultures whose crystal proteins are toxic to various insect species.
Traditional commercial B. thuringiensis bio-insecticide products are derived from “wild-type” B. thuringiensis strains, i.e., purified cultures of B. thuringiensis strains isolated from natural sources. Newer commercial B. thuringiensis bio-insecticide products are based on genetically altered B. thuringiensis strains, such as the transconjugant B. thuringiensis strains described in U.S. Pat. Nos. 5,080,897 and 4,935,353.
A characteristic of crystal proteins is their ability to coalesce to form crystals inside the B. thuringiensis mother cell. Upon lysis of the mother cell the proteins are released as crystals into the external environment. In addition, B. thuringiensis also produces non-crystal proteins that, in contrast to crystal proteins, are secreted by B. thuringiensis cells as soluble proteins into the culture medium. Secreted non-crystal proteins of B. thuringiensis include phospholipases, proteases, and β-lactamase that have little, if any, insecticidal activity. However, three secreted non-crystal proteins of B. thuringiensis designated Vip1, Vip2 and Vip3 have been reported to be toxic to coleopteran or lepidopteran insects (Estruch et al., 1996; U.S. Pat. No. 5,866,326; WO94/21795; WO96/10083). A non-crystal protein of B. thuringiensis designated CryV is reported to be toxic to lepidopteran insects (Kostichka et al., 1996). A large number of Bacillus thuringiensis isolates producing extracellular secreted insecticidal toxin proteins have been identified by a number of different investigators. Such isolates have all been shown to produce one or more of these VIP or CryV toxin proteins or closely related homologs. Coleopteran inhibitory secreted BT proteins such as TIC901, TIC1201, TIC407, and TIC417 have been previously disclosed but appear to be unrelated to the proteins of the present invention (U.S. Provisional Patent Application No. 60/485,483 filed Jul. 7, 2003; PCT/US04/21692 filed Jul. 6, 2004).
The inventors herein disclose a new class of extracellular secreted insecticidal protein toxins that do not exhibit homology to the known VIP or CryV classes of proteins. None of the one hundred thirty-seven known insect-toxic proteins of B. thuringiensis (Crickmore et al., 1998), more or less, are substantially related to the proteins of the present invention. In fact, no significant homology was found between the sequences of the proteins of the present invention and any of the thousands of protein sequences contained in the National Center for Genome Resources (GenBank), Santa Fe, N. Mex.